While visual thinking makes things simple, it certainly does not dumb them down. Part of the simplicity comes from removing unnecessary parts, leaving behind only what you need to work with. That allows you to really see exactly what it is you do have to work with. This often leads to that, "Oh, now I get it!" moment when everything finally seems to fall into place and make sense.
Once you can see things more clearly, you are able to make better decisions. Sometimes, things become so obvious it doesn't even really feel like you're making a decision at all. The right choice just jumps right at you. Or if you do need to think about it for a minute, it's much easier for you to grab it and run with it.
Check out One Squiggly Line's About Visual Thinking page to learn more.